Ejector box for a mold base



June 20, 1950 1. T. QUARNSTROM EJECTOR BOX FOR A MOLD BASE Filed June 9, 1948 V MVENTOR. WAR 1 QLHRNSTROM.

ATTORNE Y.

Patented June 20, 1950 UNITED s: TAT Es PATENT OFFICE;

Y i r 2,512,379 V EJ-ECTOR BOX FOR A MOLD BiASE Ivar T. Quarnstrom, Detroit-Mich. V Application June 9, 1948, Serial No; 31,952

(Cl. fil -4 2') 3 Claims.

This invention relates to standardmold bases used in conjunction with injection plastic molding, and more particularly to a. novel ejector box construction for use in association with such standard mold bases.

The present invention provides a novel ejector box constructio in association with the reciprocal ejector plate of the mold base.

Heretofore ejector plates have been actuated by an abutment element associated with the movable portion ofa molding machine within which a standard mold base is mounted, or on the other hand such ejector plates have been reciprocally actuated by a reciprocal shaft which extends slidably through themold base with-its end joined to the ejector plate, various means having been heretofore contemplated for cooperative engagement with said shaftfor reciprocally actuating the same. H

It is the principal object of this invention to provide a novel ejector box construction for of fecting reciprocal movementsof the mold base ejector plate as desired. M

It is the further object of this invention to provide a hollow substantially rectangular ejector box normally positioned upon the movable anchor plate of the mold base together with a pair of tubular guideel'ements joined to each other at right angles It is the further object of this invention to provide an ejector actuating shaft which incorporates a longitudinally arranged rack gear reciprocally slidable within one of said tubes, and a secondary reciprocally rotatable shaft guidi'ngly positioned within said second tube and carrying a pinion in mesh with said rack gear.

It is the still further object of this invention to provide said tubes arranged to intersect each other at their central portions, and with the common intersecting surfaces thereof being cut away to provide communication between said. tubes to permit cooperative meshing of the aforesaid pinion in one tube with theaiorementioned rack gear slidably positioned within the intersecting second tube. i

These and many other objects willsbeseen from the following specification and claims in conjunction with the appended drawing in which! Figure 1 is a perspective viewof a moldbase including an ejector box.

Figure 2 is a top plan. view of the ejector box with the ejector pl'a'te removed for illustration.

Figure 3' is an elevational section on. line 3-4 of Figure 2, but with the phantom.

Figure 4 is an elevational' section'on line- 5-4 of Figure 2 also showing the" ejector plate phantom; and

Figure 5' is a plan view of thetw'o intersecting. guide tubes normally positioned within the ejec tor box as shown in l li'gure'zl It will be understood that the above drawing illustrates merely a preferable embodiment of the invention, and that other 'embodhnents are contemplated within the scope of the claims hereafter set out.

As generally indicated in Figure l the mold base includes movable anchor plates [1 upon which the ejector'b'ox is 'lriounted, the'l'a'tter beejector plate shown in mg generally indicated by the'numeral 12'. Are

chor plates 1 l are rectangular strips upon which ejector box [2 is mounted, being suitably'secured thereto as by welding.

A backup plate ['3' is mounted upon the top of the ejector box 12 parallel. relation to an"- chor plates H and carries thereon a suitable cavity retainer plate I 4.

A stationary anchor plate i5: is shown mounted in parallel relation to retainer plate it and carrying thereunder the upper cavity retainer plate f5, there being a plurality of dowel pins I! which depend downwardly from retainer plate f6.

Corresponding Iguiding dowel pin openings are formed within cavit plate hi to cooperatively receive said dowel ins when plates It and are brought into cooperative engaging" relation for the moldin operation.

The above description merely sets out the association of the various elements which make,

up the standard mold base, within which is employed an ejector box I'2 hereafter to be described in conjunctionwith Figures 2, 3, q and 5 of the-drawing, said ejector box and its *con' struction being the subject-matter oi 'th'e' pres-- ent disclosure.

Referring to the drawing the ejector box gen erally indicated: at lz 'corisi'sts oi a pair of up right :spacedparallel plates I 8 and I llti] suitably mounted and securedoupon the top' of "ari'roh'or plates I l adj'acenttheiredges. It will .berinoted that backup plate [-3 is pos-itioned upon and su.-i=t ably secured to thetop edges of parallel plates 18 and 19,

As viewed inli'igures' l1 and 2. the ejector box includes the end wall" plates ZOIand El as well as the intermediate plates 22 and fi, all of lie ia arailel-"spaced' relation within upri ht parallel plates I3 and I9, being arranged at right angles thereto.

The plates 29, 2|, 22 and 23 are immovably secured in upright position between anchor plates I I to thereby provide the end walls for the ejector box, in association with its parallel side walls I8 and I9. The intermediate spaced upright walls 22 and 23 divide the ejector box into the two compartments 24 and 25.

The ejector box is completed by the cover 26 which is interposed between the side walls I6 and I9 and mounted and secured upon the top edges of the respective upright plate elements, 20, 2|, 22 and 23.

An upright tube 21 is centrally positioned within compartment 25 with its lower end aligned with the bottom of anchor plate II and with its upper end formed of a reduced diameter at 28 being tightly projected up into a corresponding opening within cover 26.

Longitudinally reciprocal shaft 29 is slidably positioned within the upright tube 21 as shown in Figure 3 with its upper end normally extending slightly above the top surface of cover 26.

Shaft 29 has an upper portion 36 of reduced diameter which is press-fit within a corresponding opening in the central portion of ejector plate 3|, or may be otherwise suitably secured thereto.

As shaft 29 extends partially above. cover 26 before terminating in the portion of reduced diameter it is seen that said ejector plate is normally maintained in parallel spaced relation to the upper surface of cover 26.

A suitable rack gear 32 is longitudinally arranged throughout the length of shaft 29 with the outer edges of said gear cooperatively and slidably bearing against the inner surface of tube 21.

A second tube 33 is arranged at right angles to tube 21 with corresponding intersecting portions of tubes 21 and 33 being cut away to permit said tubes to be centrally interconnected as shown in Figure 5, said tubes being suitably secured to each other as by welding. As viewed in Figure 2 tube 33 extends through compartment 25 of ejector box I2 with its end portions 34 of reduced diameter being press-fitted within corresponding openings of the upright parallel plates 26 and 22.

Rotatable shaft 35 is journalled through tube 33, and through a, corresponding second such tube 33 which is positioned within and through the other compartment 24 forming a part of ejector box I2, the construction and arrangement of the second tubular element 33 being identical with that above described with respect to the corresponding aligned tube within compartment 25.

It will be noted from the drawing that there are two sets of intersecting tubular elements 21 and 33 with one extending through each of the compartments 24 and 25 which form a part of ejector box I2. Naturally the secondary upright tube 21 is arranged in parallel spaced relation to the first mentioned corresponding tube 21 with its upper endbeing similarly secured through a corresponding opening in cover 26.

Furthermore there will be a second corresponding reciprocal shaft 29 within said second tube 21, also carrying a suitable longitudinally arranged rack gear. I

Rotatable shaft 35 is thus journalled through both of the aligned supporting tubes 33, however it is contemplated that the ejector box may be 7 constructed with only one compartment, and with only one set of intersecting tubes 21 and 33.

The rotatable shaft 35 has formed thereon the pinion gear 36 which extends substantially through both of the aligned tubes 33, being in meshing engagement with both of the upright rack gears 32 which form a part of reciprocal ejector plate actuating shafts 29. On the other hand two separate pinions could be mounted upon shaft 35 in spaced relation for separate cooperating meshing engagement with the respective rack gears upon shafts 29.

The intersecting cutaway portions of the tubes 21 and 33 thus permit communication between the interiors of the tubes 21 and 33 thereby permitting the cooperating meshing engagement of pinion 36 with the corresponding rack gears 32, or one rack gear if only one such shaft 29 is employecl.

The outer end 31 of shaft 35 is squared to permit the attachment of an actuating handle or other element whereby shaft 35 may be reciprocally actuated or rotated as desired to cause up or down movements of ejector plate 3I.

As viewed in Figure 1 ejector plate 3I is slidably positioned above the cover 26 of ejector box I2 and between the upright side walls I8 and I9, there being a plurality of ejector plate return pins 38 which extend upwardly from said ejector plate and thru corresponding openings in plates I3 and I4.

In normal operation pins 38 extend above the surface of cavity plate I4 and are cooperatively engageable with the bottom surface of cavity plate I6 as the two plates I4 and I6 are brought together for the molding operation, said return pins 36 acting to project or return ejector plate 3I to its normal inoperative position as viewed in Figures 3 and 4.

Having described my invention, reference should now be hadto the claims which follow for determining the scope thereof.

I claim:

1. In a mold base including stationary and movable anchor plates and cavity retainer plates associated therewith, an ejector box including in combination, parallel upright side Walls on said movable anchor plates, a'backup plate positioned over the tops of said walls and in supporting relation to a cavity retainer plate, an ejector box cover between said walls and in spaced relation to said backup plate, a reciprocal ejector plate extending between said cover and backup plate, an upright reciprocal shaft slidably positioned through said cover and joined to said ejector plate, a rack gear on said shaft, a transverse rotatable shaft carrying a pinion in mesh with said rack gear and extending outwardly from said mold base, and a pair of cylindrical tubes intersecting each other at their central portions and joined to each-other at right angles with their common intersecting surfaces being cut away to provide communication between said tubes. and with their ends secured within said mold base, said tubes respectively providing guide supports within which said shafts are positioned.

2. In a mold base having a reciprocal ejector plate, the combination, of a hollow rectangular ejector box, a cover therefor below and in parallel relation to said ejector plate, a pair of tubes intersecting each other at their central portions and joined to each other at right angles with their common intersecting surfaces being cut away to provide communication between said tubes,

the ends of one of said tubes supportably extending into the side walls of said box. with one end of the other tube being joined to and extending through said cover, a longitudinally reciprocal shaft carrying a rack gear slidably positioned within said second mentioned tube and joined at one end to said ejector plate, and a shaft carrying a pinion rotatably positioned within the other tube with said pinion in mesh with said rack gear.

3. The combination, of a hollow rectangular ejector box, a cover therefor, a pair of tubes intersecting each other at their central portions 1 and joined to each other at right angles, with their common intersecting surfaces being cut away to provide communication between said tubes, the ends of one ofsaid tubes supportably extending into the side walls of said box and secured thereto, with one end of the other tube being joined to and extending through said cover, a longitudinally reciprocal shaft carrying a rack 20 gear reciprocally slidable within the latter tube with one end projecting through and above said cover, a reciprocal ejector plate lying parallel to said cover and joined to said end, and :a reciprocally rotatable shaft carrying a pinion journalled within said other tube and in mesh with said rack gear.

IV AR T. QUARNSTROM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS,

Number Name Date 2,217,661 Anderson Oct. 15, 1940 2,227,966 Emsley Jan. 7, 1941 2,398,893 Quarnstrom Apr. 23, 1946 2,419,089 Quarnstrom Apr. 15, 1947 

